Vitamins and Minerals: A Practical Reference for Everyday Eating

Why Micronutrients Matter

Vitamins and minerals — collectively called micronutrients — are compounds the body needs in relatively small amounts to function properly. Unlike macronutrients (protein, fat, and carbohydrates), they don't supply calories, but they enable nearly every biological process: converting food into energy, building bone and tissue, supporting immune defense, and regulating hormones.

Most healthy adults can meet their micronutrient needs through a varied diet. However, certain groups — including pregnant individuals, older adults, those with restrictive diets, and people with specific health conditions — are at higher risk for gaps. Understanding what each nutrient does and where it comes from is a useful starting point for evaluating your own eating patterns.

For a broader view of how dietary needs shift at different points in life, see how nutrient requirements change across life stages.

Key Vitamins: Functions, Sources, and Deficiency Signs

Vitamins are divided into two categories based on how the body stores them:

• Fat-soluble vitamins (A, D, E, K) are stored in body fat and the liver. They can accumulate to excess if over-supplemented.
• Water-soluble vitamins (C and the eight B vitamins) are not stored significantly; excess is generally excreted in urine, making regular dietary intake important.

Vitamin D

Supports calcium absorption, bone density, immune function, and mood regulation. The body synthesizes it through sun exposure, but many Americans — especially those in northern climates or who spend little time outdoors — have insufficient levels. Dietary sources include fatty fish, egg yolks, and fortified dairy or plant milks. Deficiency is associated with weakened bones, fatigue, and impaired immunity.

Vitamin B12

Essential for nerve function, red blood cell formation, and DNA synthesis. Found almost exclusively in animal products (meat, fish, dairy, eggs), making deficiency a real concern for vegans and vegetarians without supplementation. Early signs include fatigue, tingling in the hands or feet, and cognitive fog.

Folate (Vitamin B9)

Critical for cell division and especially important during pregnancy to prevent neural tube defects. Rich sources include dark leafy greens, legumes, and fortified grains. The synthetic form, folic acid, is commonly used in supplements and fortified foods.

Vitamin C

A powerful antioxidant that supports immune function, collagen synthesis, and iron absorption from plant foods. Found in citrus fruits, bell peppers, strawberries, and broccoli. Deficiency (scurvy) is rare in the U.S. but can occur with severely limited fruit and vegetable intake.

Essential Minerals: What They Do and Where to Find Them

Minerals are inorganic elements that support structural roles (like calcium in bones) and regulatory functions (like potassium in nerve signaling).

Iron

Needed to produce hemoglobin, the protein in red blood cells that carries oxygen. Two forms exist: heme iron (from animal foods, more easily absorbed) and non-heme iron (from plant foods). Pairing plant-based iron sources with vitamin C boosts absorption. Iron deficiency — one of the most common nutritional shortfalls globally — can cause fatigue, paleness, and difficulty concentrating. See which foods are genuinely high in iron for a detailed breakdown.

Calcium

The most abundant mineral in the body, primarily stored in bones and teeth. Also involved in muscle contraction and nerve transmission. Sources include dairy, fortified plant milks, tofu, almonds, and leafy greens like kale. Adequate vitamin D is required for effective calcium absorption.

Magnesium

Involved in over 300 enzymatic reactions, including energy production, muscle function, and blood sugar regulation. Found in nuts, seeds, legumes, whole grains, and dark chocolate. Many Americans fall short of recommended intakes.

Potassium

Helps maintain normal blood pressure, fluid balance, and heart rhythm. Bananas get the spotlight, but potatoes, beans, leafy greens, and dairy are also excellent sources. Low intake is associated with higher blood pressure risk.

To put these nutrients in context with food choices and labeling, understanding food marketing language can help you evaluate nutritional claims more critically.

This article is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Speak with a qualified healthcare provider before making changes to your diet or beginning any supplementation regimen.